You corrupt one opening, door, portal, or other threshold you can see within range with invisible, poisonous fumes. When you cast this spell, choose one threshold up to 10 feet wide and up to 10 feet tall. Each creature that passes through the opening must make a Constitution saving throw. On a failed save, a creature takes 2d4 poison damage and is poisoned for 1 minute. On a successful save, a creature takes half the damage and isn’t poisoned. At the end of each of its turns, a poisoned creature can make another Constitution saving throw, ending the poisoned condition on itself on a success.